Lithograph with one-dimensional trigger mask and method for production of digital holograms in a storage medium

ABSTRACT

The present invention relates to a method of producing digital holograms in a storage medium, in which the technical problem of writing computer-generated holograms by means of optical lithography as quickly as possible and with little effort with simultaneous accurate control of the timed triggering and the positioning of the write beam is achieved in that a write beam is focused onto the storage medium and moved one-dimensionally relative to the storage medium, in that a scanning beam is focused onto a trigger mask having a plurality of trigger lines and moved one-dimensionally transversely relative to the trigger lines, the movement of the scanning beam being coupled with the movement of the write beam, in that, during the scanning of the trigger lines, a timed trigger signal is generated as a function of the arrangement of the trigger lines, in that, with the aid of the timed trigger signal, the intensity of the write beam on the storage medium is controlled, and in that the hologram is written line by line by introducing radiation energy point by point, the storage medium being displaced transversely with respect to the scanning direction of the lines by a predefined distance to write adjacent lines of the hologram.  
     The technical problem is also solved by a lithograph for producing digital holograms.

[0001] The present invention relates to a lithograph for producingdigital holograms in a storage medium. Furthermore, the inventionrelates to a method of producing digital holograms in a storage medium.

[0002] Digital holograms are two-dimensional holograms which consist ofindividual points with different optical properties and from which, whenilluminated with a coherent electromagnetic wave, in particular a lightwave, images and/or data are reproduced by means of diffraction intransmission or reflection. The different optical properties of theindividual points can be reflective material properties, for example asa result of surface topography, varying optical path lengths in thematerial of the storage medium (refractive indices) or color values.

[0003] The optical properties of the individual points are calculated bya computer, what are known as computer-generated holograms (CGH) arethus involved. With the aid of the focused write beam, during thewriting of the hologram, the individual points of the hologram arewritten into the material, the focus being located in the region of thesurface or in the material of the storage medium. In the region of thefocus, focusing has the effect of a small area of action on the materialof the storage medium, so that a large number of points of the hologramcan be written on a small area. The optical property of the respectivelywritten point in this case depends on the intensity of the write beam.For this purpose, the write beam is scanned in two dimensions over thesurface of the storage medium with varying intensity. The modulation ofthe intensity of the write beam is in this case carried out either viainternal modulation of the light source, for example a laser diode, orvia external modulation of a write beam outside the light source, forexample with the aid of optoelectronic elements. Furthermore, the lightsource can be formed as a pulsed laser whose pulse lengths can becontrolled, so that control of the intensity of the write beam can becarried out by the pulse lengths.

[0004] As a result of the scanning of the intensity-modulated writebeam, an area with an irregular point distribution is thus produced, thedigital hologram. This can be used to identify and individualize anydesired objects.

[0005] Scanning lithographic systems are intrinsically widespread. Forexample, scanning optical systems are incorporated in conventional laserprinters. However, these systems cannot be used for the production ofholograms, since the requirements for this intended application differconsiderably from those in laser printers. In the case of good printingsystems, the resolution is around 2500 dpi while, in the production ofholograms, a resolution of about 25 000 dpi is required. In addition, indigital holography, only comparatively small areas are written. Theseare, for example, 1 to 5 mm², other sizes also being possible. Theaccuracy of the write pattern in the case of a lithograph for theproduction of digital holograms of, for example, 1000×1000 points on anarea of 1×1 mm² must be about ±0.1 mm in both orthogonal directions.Furthermore, the writing speed should be about 1 Mpixel/s, in order thatin each case a hologram can be written in a time of about 1 s.

[0006] Digital holograms can be produced by means of conventionalscanning methods, with which the angle of the incident beam is varied bystationary optics. For example, scanning mirror lithographs withgalvanometer and/or polygonal scanners operate on this principle.

[0007] In all the scanning methods known hitherto, one disadvantage isthat, in a lithograph of simple structure, no timed control of the writebeam is possible which is capable of maintaining a predefined pointpattern of the digital hologram at the writing speeds to be achieved.

[0008] The present invention is therefore based on the technical problemof writing computer-generated holograms by means of optical lithographyas quickly as possible and with little effort with simultaneous accuratecontrol of the timed triggering and the positioning of the write beam.

[0009] The technical problem indicated previously is achieved by amethod of producing digital holograms in a storage medium, in which awrite beam is focused onto the storage medium and movedone-dimensionally relative to the storage medium, in which a scanningbeam is focused onto a trigger mask having a plurality of trigger linesand is moved one-dimensionally transversely relative to the triggerlines, the movement of the scanning beam being coupled with the movementof the write beam, in which, during the scanning of the trigger lines, atimed trigger signal is generated as a function of the arrangement ofthe trigger lines, in which, with the aid of the timed trigger signal,the intensity of the write beam on the storage medium is controlled, andin which the hologram is written line by line by introducing radiationenergy point by point, the storage medium being displaced transverselywith respect to the scanning direction of the lines by a predefineddistance to write adjacent lines of the hologram.

[0010] One-dimensional movement in the sense of the present inventionmeans a movement which extends substantially in one direction. Aone-dimensional movement is therefore in particular a rectilinearmovement, but a one-dimensional movement in the sense of the inventioncan also be along a curved line, that is to say deviating from astraight line.

[0011] According to the invention, it has been recognized that, with theaid of a scanning beam coupled in its movement to the write beam, atimed trigger signal can be generated with a one-dimensional triggermask similar to a bar code. In this case, the trigger lines arepreferably arranged in parallel, that is to say in an orthogonalpattern, but this is not absolutely necessary. With the aid of the timedtrigger information and an additional item of intensity informationwhich, in principle, can be generated independently of the trigger mask,the digital hologram can be written successively point by point inlines. Therefore, the movements of the write beam and the storage mediumare coordinated with one another. Once a current line has been written,then for example the storage medium is displaced by a predefineddistance, so that the further line can then be written. It is likewisepossible to displace the storage medium continuously and to write thelines of the hologram into the material of the storage medium during thedisplacement of the storage medium transversely with respect to thescanning direction.

[0012] As explained previously, during the scanning of the triggerlines, a timed trigger signal is generated as a function of thearrangement of the trigger lines. In particular, the timed triggersignal can be generated when the scanning beam coincides with one of thetrigger lines to be scanned. In this case, coincidence means either thatreaching or leaving the trigger line or an arbitrary intermediate regionbetween the trigger lines is measured as a threshold value of a beamreflected or transmitted by the trigger mask, or that the trigger maskhas active elements which can generate the timed trigger signal at apredefined illumination intensity. This value is set within themeasurement accuracy such that the control can be carried out at therequired speed.

[0013] The scanning beam is preferably moved in a predefined movementrelationship with the write beam. Thus, the scanning beam can scan atrigger mask whose area is greater than the region of the storage mediumto be written. If the trigger mask is, for example, 10 times larger thanthe hologram to be produced, then the movement of the scanning beam isenlarged in the ratio 10:1 in proportion to the movement of the writebeam. If, therefore, for example a hologram with an area of 1×1 mm² isto be written, the scanning beam scans a trigger mask with an area of10×10 mm².

[0014] Furthermore, it is preferred for the scanning beam to be focusedto a size which corresponds at most to the trigger line dimension of thetrigger mask. This ensures that coincidence with the trigger line issensed sufficiently accurately and a sufficiently accurate timed triggersignal can be generated.

[0015] The optical properties of the trigger lines can be formed indifferent ways, in each case use being made of techniques which areknown per se from the prior art, in particular from optical storagemedia such as compact disc (CD) or digital versatile disc (DVD).

[0016] In a first embodiment, the trigger lines of the trigger mask havea reflectance differing from the surrounding surface laterally besidethe trigger lines, so that the beam reflected from the surface of thetrigger mask can be detected by a detector. The trigger signal is thenderived from the intensity of the reflected scanning beam focused on thedetector surface.

[0017] In a second embodiment, the trigger lines of the trigger maskhave transmission properties differing from the surrounding surfacelaterally beside the trigger lines, so that the beam transmitted by thetrigger mask can be detected by a detector. The trigger signal is thenderived from the intensity of the transmitted beam measured in this way.

[0018] Sections with reflective and with transmissive properties canalso be combined with one another in a trigger line.

[0019] In a third embodiment, the trigger lines on the trigger mask havea surface structure, for example in the form of grooves, so that thebeam refractively diffracted at the surface of the trigger mask can bedetected. The trigger signal is then derived from the intensity of thereflected beam, which results substantially from the superimposition ofthe zeroth and the two first orders of diffraction.

[0020] All the embodiments of the invention mentioned previously by wayof example are based on the fact that the scanning beam is influenced bythe optical properties of the trigger mask in such a way that thecoincidence with a trigger line can be detected from this and may beconverted into a control signal for controlling the intensity of thewrite beam.

[0021] A further configuration of the trigger mask consists in itshaving active pixels and thus being able to produce the timed triggersignal directly. By means of driving the pixels differently, it is thusalso possible for different trigger tracks to be produced withoutreplacing the trigger mask per se.

[0022] The active trigger mask used is preferably a spatial lightmodulator (SLM), with which a time-variably adjustable trigger mask canbe implemented. According to a second teaching of the present invention,the technical problem listed above is solved by a lithograph having thefeatures of claim 15.

[0023] The previously described functioning of the present invention andits preferred configurations can also advantageously be used in ascanning, in particular confocal, microscope. In a microscope of thistype, the surface to be examined is scanned or observed with a lightbeam and the reflected light intensity is measured. During the scanningof the surface, the image is then assembled from the measuredintensities of the reflected light. The surface is therefore scanned ina pattern, as has been described previously.

[0024] In the present case, for this purpose, a beam splitter isarranged in the beam path of the reflected beam, in front of orpreferably behind the objective, in order to lead the reflectedradiation to an optical sensor. The latter measures the reflectedintensity.

[0025] With a microscope of this type, the technical problem ofobserving or scanning a surface as quickly as possible and with littleeffort is solved. This is in accordance with the technical problem onwhich the lithograph previously described is based. The advantagespreviously described for the lithograph are likewise achieved in amicroscope of this type.

[0026] In the following text the invention will be explained in moredetail using exemplary embodiments and with reference to the appendeddrawing, in which:

[0027]FIG. 1 shows an exemplary embodiment of a lithograph according tothe invention,

[0028]FIG. 2 shows an exemplary embodiment of a trigger mask, and

[0029]FIG. 3 shows a microscope according to the invention with astructure which corresponds substantially to the structure of thelithograph illustrated in FIG. 1.

[0030]FIG. 1 shows a first exemplary embodiment of a lithograph 2according to the invention for producing digital holograms in a storagemedium 4 which is arranged on a carrier 6. A light source 8 forproducing a write beam 10 preferably has a laser or a laser diode, sothat the write beam 10 is formed as a laser beam.

[0031] The lithograph 2 also has drive means for the one-dimensionalmovement of the write beam 10 relative to the storage medium 4, whichare formed as a galvanometrically driven scanning mirror 12 and, forexample, deflect the writing beam in the direction at right angles tothe plane of the drawing of FIG. 1. The mirror 12 therefore constitutesan x-scanning mirror arrangement. Instead of the galvanometric scanningmirror 12, a rotatable polygonal mirror can also be used.

[0032] Optionally, a beam spreader or collimator 15 is also arranged inthe beam path, behind the scanning mirror 12, in order to produce awidened write beam 10.

[0033] A first objective 16 focuses the write beam 10 onto the storagemedium 4 to be written, so that, at the focus 17, depending on thefocused intensity of the write beam 10, the optical property of thestorage medium 4 is changed or remains unchanged.

[0034] According to the invention, a two-dimensional trigger mask 18 isprovided, onto which a scanning beam 22 coupled out of the write beam 10by a beam splitter 20 is focused at a focus 25 by a second objective 24.

[0035] The scanning beam 22 is produced by a second light source 26 andis coupled into the beam path of the write beam 10 in front of the firstscanning mirror 12 by a beam splitter 28. The scanning beam 22 has awavelength or polarization which differs from the write beam 10, so thatthe beam splitter 28 is formed as a dichroic or polarizing beamsplitter. The beam splitter 20 is then correspondingly formed so as tobe dichroic or polarizing, in order to couple the scanning beam 22 outof the common beam path.

[0036] The scanning beam 22 is therefore independent of the intensitymodulation of the write beam 10, so that the latter can also be switchedoff, that is to say set with an intensity equal to zero.

[0037] On the other hand, it is also possible to couple the scanningbeam 22 out of the write beam as a part beam without the scanning beam22 having to be produced by a separate light source. The beam splitters20 and 28 are then formed as partly transparent beam splitters.

[0038] The two objectives 16 and 24 in each case have three lenses of afocusing lens system. However, the precise configuration of theobjectives 16 and 24 is unimportant. The objectives 16 and 24 canpreferably be formed such that their angular deflections in the xdirection depend linearly on each other, which produces linear couplingbetween the movements of the foci 17 and 25.

[0039] As emerges from the structure of the lithograph 2 according toFIG. 1, the drive means, that is to say the scanning mirror 12, do notdrive just the write beam 10 but also the scanning beam 22. This isbecause the beam splitter 20 is arranged behind the scanning mirror 12in the beam path of the write beam 10. Thus, the scanning beam 22 ismoved one-dimensionally in the same way as the write beam 10, so thatthe scanning beam 22 is moved relative to the surface of the triggermask 18. This results in the movement of the scanning beam 22 beingcoupled with the movement of the write beam 10.

[0040] Furthermore, a detector 30′ or a detector 30″ is provided,alternatively or additionally, to pick up the scanning beam 22 of whichthe intensity is varied by the optical properties of the respectivetrigger lines of the trigger mask 18. The two different positions areillustrated in FIG. 1. The functioning of the detectors 30′ and 30″ issimilar and will be explained in more detail further below.

[0041] Furthermore, control means 36 are provided for generating atrigger signal, connected to the detectors 30′ and/or 30″.

[0042] For this purpose, lines 40 and 42 (illustrated as interrupted atthe points A in FIG. 1) are provided. The timed trigger signal is thengenerated in accordance with the signals from the detectors.

[0043] Furthermore, the control means 36 generate an intensity controlsignal, which is transmitted to the light source 8 via a line, notillustrated, in order to control the intensity of the write beam 10. Thecontrol means 36 are formed as a computer. By means of the intensitycontrol signal that is transmitted, the write beam 10 is modulated as afunction of the position of the focus 25 of the scanning beam 22 on thetrigger mask 18, which is coupled with the position of the focus 17 ofthe write beam 10 on the storage medium 4.

[0044] In other words, the write beam 10 is set to write hologram pointswith two or more different intensity values. In the case of binarywriting, the intensity is switched to and fro between two differentvalues, depending on whether a point is to be written or not. Likewise,writing hologram points with a gray value graduation is possible andpractical.

[0045] If, however, as was described above, the scanning beam 22 iscoupled out of the write beam 10 as a part beam without a separate lightsource being required, then, in order to register the focus 25 on thetrigger mask 18, however, it is necessary for the lower or lowestintensity value of the write beam 10 not to be equal to zero. Thisensures that the scanning beam 22 always has a minimum intensity for thegeneration of a trigger signal.

[0046] Furthermore, in the case of the structure of the lithograph 2illustrated in FIG. 1, a length-related transmission ratio between themovement of the write beam 10 on the storage medium 4 and the scanningbeam 22 on the trigger mask 18 is predefined. This is implemented bymeans of different focal lengths of the two objectives 16 and 26. If,for example, the focal length of the first objective 16 is smaller by afactor 10 than the focal length of the second objective 24, then themovement of the focus 25 of the scanning beam 22 on the trigger mask 18is greater by the same factor 10 times than the movement of the focus 17on the surface of the storage medium 4. In FIG. 1, only a focal lengthratio of about 2 is illustrated, for reasons of space. However, thisillustrates that a specific ratio is unimportant in the presentconfiguration of the invention.

[0047] Furthermore, the carrier 6 is connected to a drive 50,illustrated schematically, which displaces the storage medium step bystep between two lines of the hologram to be written in each case. Thedirection of the displacement is illustrated by a double arrow in FIG. 1and runs horizontally in the plane of the drawing of FIG. 1. As aresult, it is possible to write the lines of the hologram in anorthogonal pattern. In addition, the drive can also displace the carrier6 continuously, so that the lines are written in a pattern which is notorthogonal if the storage medium 4 is moved during the scanning with theaid of the scanning mirror 12.

[0048] As FIG. 2 shows, the trigger mask 18 has a plurality of triggerlines 44. These are arranged in an orthogonal pattern and havesubstantially identical spacings from one another. In quite generalterms, however, the trigger lines 44 can be present in a predefinedarrangement in which the trigger lines even have a form which runsarbitrarily, therefore also curved, and have varying spacings from oneanother. This is because the arrangement of the trigger lines 44reproduces the point pattern of the digital hologram to be written.

[0049] The scanning beam scans the trigger lines transversely,preferably at right angles to their course, similar to the case whenregistering a bar code. Because of the elongated extent of the triggerlines 44, accurate adjustment of the scanning beam 22 on the triggermask 18 is therefore not important. At the start and/or at the end ofthe trigger lines 44, it is preferable for specific codes to be formedin the scanning direction, which make it possible for a start and/or anend signal to be generated from the beam influenced by the trigger mask.In this case, the codes can, for example, be contained in trigger linesof different widths, similar to the case of a bar code.

[0050] The trigger mask 18 can have a surface with different reflectiveproperties. For this purpose, the trigger mask 18 is to some extentprovided with a reflective layer. Likewise, the different reflectiveproperties can be formed as different colorations of the material of thetrigger mask. Likewise, different refractive properties of the materialcan effect the different reflective properties. Finally, the triggermask can be formed as a spatial light modulator (SLM). As a result, atime-variable trigger mask is advantageously implemented.

[0051] Furthermore, the trigger mask 18 can have a surface with atopographical surface structure, at which the scanning beam 22 isreflected diffractively.

[0052] For both configurations of the beam guide mask, which reflectsthe scanning beam in the direction back to the light source 26, anoutput beam coupler 46 is provided in the beam path of the scanning beam22, in front of the scanning mirror 12 in the beam direction. Saidcoupler leads the reflected scanning beam 22 to the detector 30′. There,the detection signal is generated as the control signal for the controlmeans 36.

[0053] Furthermore, the trigger mask 18 can have a surface withdifferent transmission properties. The scanning beam 22 is therefore letthrough at different intensities. The proportion of the scanning beam 22that is let through is focused by optics 48 onto the surface of thedetector 30″. There, the control signal for the control means 36 is thengenerated and is transmitted via the line 42.

[0054] In this case, too, the material of the trigger mask 18 can beformed in different ways. The different transmission properties can beproduced by different colorations of the intrinsically translucentmaterial. However, in this case, too, the trigger mask 18 can be formedas a spatial light modulator (SLM). As a result, a time-variabletransmitting trigger mask is advantageously implemented.

[0055] The control means 36 for generating a timed trigger signal havecomputer means which are connected to the detectors 30′ and/or 30″. Saidmeans compare the signal picked up by the detectors with desired values,so that the control signal for the intensity control is generated.

[0056] The control means 36 can likewise be used to generate anintensity control signal. For this purpose, the control means 36 havestorage means, in which intensity values relating to the predefinedpositions along the tracks 44 are stored, are in each case read out andused to control the intensity of the light source 8.

[0057] A further feature of the configurations previously described ofthe lithograph is that the distance between the storage medium 4 and theobjective 16 in FIG. 1 can be adjusted variably. This is identified by adouble arrow designated “Z”. For an adjustment of the distance in the zdirection, means not illustrated in the Figures are provided. These canbe any linear adjusting means which can be driven by motor or by hand.By means of adjusting the distance, the position of the focus in thestorage medium 4 can be arranged at various depths; likewise adjustmentof the focus with storage media 4 of different thicknesses is possible.Finally, at least two digital holograms can be written into differentplanes within the storage medium 4, in order to produce what are knownas multilayer holograms.

[0058]FIG. 3 illustrates a microscope according to the invention which,in its structure, corresponds to the lithograph illustrated in FIG. 1.Therefore, identical designations designate identical components tothose as have been described in connection with FIG. 1, even if, indetail, other designations are used which identify the differencebetween writing and observing.

[0059] In addition to the structure illustrated in FIG. 1, a deflectionplane 60 is arranged in the beam path of the light reflected from thesurface, behind, that is to say above, the objective 16. This can beimplemented by means of a semitransparent mirror or a beam splitter andhas no influence or only an insignificant influence on the observationbeam.

[0060] The deflection plane 60 deflects the reflected beam laterally, tothe left in FIG. 7, so that it strikes a photosensor 62 which measuresthe intensity of the reflected light.

[0061] By varying the observation beam 10 relative to the object 4 to beviewed under the microscope, the surface is then scanned and thereflectance is measured point by point. An image of the scanned surfacecan thus be assembled.

[0062] If, then, the light beam emitted by the light source 8, which canbe designated an observation beam in the microscope, is produced with asubstantially identical intensity, then the measured intensity of thereflected beam is a measure of the reflectance of the scanned surface.

1. A method of producing digital holograms in a storage medium, whereina write beam is focused onto the storage medium and movedone-dimensionally relative to the storage medium, a scanning beam isfocused onto a trigger mask having a plurality of trigger lines andmoved one-dimensionally transversely relative to the trigger lines, themovement of the scanning beam being coupled with the movement of thewrite beam, during the scanning of the trigger lines, a timed triggersignal is generated as a function of the arrangement of the triggerlines, with the aid of the timed trigger signal, the intensity of thewrite beam on the storage medium is controlled, and the hologram iswritten line by line by introducing radiation energy point by point, thestorage medium being displaced transversely with respect to the scanningdirection of the lines by a predefined distance to write adjacent linesof the hologram.
 2. The method as claimed in claim 1, wherein thetrigger lines are arranged in parallel, preferably in an orthogonalpattern.
 3. The method as claimed in claim 1, wherein with the aid ofthe timed trigger information and an additional item of intensityinformation, the digital hologram is written successively point by thepoint in lines.
 4. The method as claimed in claim 3, wherein theintensity information is generated independently of the trigger mask. 5.The method as claimed in claim 1, wherein the storage medium is keptunchanged with respect to the write beam as a line is written and ismoved by the spacing of one line during a line change of the write beam.6. The method as claimed in claim 1, wherein the storage medium isdisplaced continuously during the writing.
 7. The method as claimed inclaim 1, wherein the scanning beam is moved in a predefined movementrelationship with the write beam.
 8. The method as claimed in claim 1,wherein the scanning beam is focused to a size which corresponds at mostto the trigger line dimension of the trigger mask.
 9. The method asclaimed in claim 1, wherein the trigger lines of the trigger mask have areflectance differing from the surrounding surface laterally beside thetrigger lines, and in which the trigger signal is derived from theintensity of the beam reflected from the surface of the trigger mask.10. The method as claimed in claim 1, wherein the trigger lines of thetrigger mask have a transmission property differing from the surroundingsurface laterally beside the trigger lines, and in which the triggersignal is derived from the intensity of the beam transmitted through thetrigger mask.
 11. The method as claimed in claim 1, wherein the triggerlines of the trigger mask have a surface structure, for example in theform of grooves, and in which the trigger signal is derived from theintensity of the beam reflectively diffracted at the surface of thetrigger mask.
 12. The method as claimed in claim 1, wherein the triggermask has active pixels and in which the timed trigger signal isgenerated directly by the active pixels.
 13. The method as claimed inclaim 12, wherein the active trigger mask used is a spatial lightmodulator.
 14. The method as claimed in claim 1, wherein the distancebetween the objective and the storage medium is adjusted for writing atdifferent depths within the storage medium.
 15. A lithograph forproducing digital holograms in a storage medium in particular forimplementing a method as claimed in claim 1, having a light source forproducing a write beam, having drive means for the one-dimensionalmovement of the write beam relative to the storage medium and having afirst objective for focusing the write beam onto the storage medium tobe written, wherein a trigger mask having a plurality of trigger linesis provided, means of producing a scanning beam are provided, a secondobjective for focusing the scanning beam onto the trigger mask isprovided, the drive means move the scanning beam relative to the surfaceof the trigger mask, the movement of the scanning beam being coupledwith the movement of the write beam, a detector is provided to pick upthe scanning beam whose intensity is varied by the optical properties ofthe trigger lines, control means for generating a trigger signal as afunction of the signal from the detector.
 16. The lithograph as claimedin claim 15, wherein the control means are also provided to generate asignal for controlling the intensity of the write beam.
 17. Thelithograph as claimed in claim 15, wherein the drive means are formed asan x/y scanning mirror arrangement for moving the write beam and themeans of producing the scanning beam have means for coupling out part ofthe write beam as a scanning beam in the beam path of the write beambehind the drive means.
 18. The lithograph as claimed in claim 17,wherein the means of producing the scanning beam have a second lightsource for producing a scanning beam with a wavelength or polarizationdiffering from the write beam and input coupling means for coupling thescanning beam into the beam path of the write beam in front of the drivemeans and the output coupling means couple out the scanning beam. 19.The lithograph as claimed in claim 15, wherein means for moving thestorage medium relative to the write beam are provided.
 20. Thelithograph as claimed in claim 15, wherein a length-based step-up ratiobetween the movement of the scanning beam on the trigger mask and of thewrite beam on the storage medium is provided.
 21. The lithograph asclaimed in claim 20, wherein the focal length of the second objective isgreater by a predefined factor than the focal length of the firstobjective.
 22. The lithograph as claimed in claim 15, wherein thetrigger mask has a plurality of trigger lines.
 23. The lithograph asclaimed in claim 22, wherein the trigger lines are arranged in apattern, in particular an orthogonal pattern.
 24. The lithograph asclaimed in claim 15, wherein the trigger mask has a surface withdifferent reflective properties.
 25. The lithograph as claimed in claim24, wherein the trigger mask is formed as a spatial light modulator. 26.The lithograph as claimed in claim 15, wherein the trigger mask has asurface with a topographical surface structure, at which the scanningbeam is reflected.
 27. The lithograph as claimed in claim 15, whereinthe trigger mask has a surface with different transmission properties.28. The lithograph as claimed in claim 27, wherein the trigger mask isformed as a spatial light modulator.
 29. The lithograph as claimed inclaim 27, wherein focusing optics for focusing the transmitted radiationonto the detector are provided.
 30. The lithograph as claimed in claim15, wherein means are provided for adjusting the distance between thestorage medium and the objective.
 31. A microscope for scanning anobject, having a light source for producing a scanning beam, havingdrive means for the one-dimensional movement of the scanning beamrelative to the object and having a first objective for focusing thescanning beam onto the object, wherein a trigger mask having a pluralityof trigger lines is provided, means of producing a scanning beam areprovided, a second objective for focusing the scanning beam onto thetrigger mask is provided, the drive means move the scanning beamrelative to the surface of the trigger mask, the movement of thescanning beam being coupled with the movement of the scanning beam, adetector is provided to pick up the scanning beam whose intensity isvaried by the optical properties of the trigger lines, and control meansfor producing a trigger signal as a function of the signal from thedetector.
 32. The microscope as claimed in claim 31, having one or morefeatures of claim 15.